as we all know, Bungie connects everything to the number seven. If the "seeding the galaxy" theory were true, and the Forerunner did set up certian paths for each race to follow and then unite, then if you include the "new" races (i.e. Brutes and Prophets) you end up with seven species that the Forefunner made.

The Sevens have it! I guess we have no surprises to look forward to in the sequel... shucks ;)